Fourth-generation warfare, as the authors explain, represents an evolution of warfare away from states and toward nonstate actors—that is, away from the Westphalian concept of war as being the monopoly of the state, and toward warfare that can be waged by nonstate actors such as families, clans, tribes, and business enterprises both legal and illegal (Introduction). As the authors point out, nonstate actors regularly waged war before the 1648 Peace of Westphalia, and now they are beginning to take up that role again, leading away from two-sided wars and back to many-sided wars. The authors argue that this multisided understanding of war has come back due to a crisis of the legitimacy of the state (cf. Bobbitt's The Shield of Achilles and Terror and Consent).

So how does one prepare for, and fight, 4GW? The authors undertake this question, drawing examples from recent 4GW conflicts as well as speculative scenarios from a future war. Their viewpoint is that of a state's armed forces trying to wage war with nonstate actors; the running example is a fictionalized scenario in which the US Army has occupied "Inshallahland." Throughout the book, they argue that the strategic, tactical, and operational levels of warfare should be addressed in terms of physical, mental, and moral aspects; they suggest a grid for planning how these different axes of factors will interrelate. Such a grid is important because things that are productive at one level can be counterproductive at others.

The authors advocate an approach in which light infantry units interact constantly with the occupied population, being exposed but also solving problems, creating ties, and demonstrating that they will bring stability and safety—that is, providing the benefits that a State has to offer. Everything is a PsyOp—that is, every act is understood as having a persuasive component.

These light infantry units also handle the bulk of the fighting. The authors essentially want to see the light infantry units functioning as special forces who can live off the land, move with a light footprint, and out-hunt irregular forces. They even include a sort of 12-week syllabus for training light infantry units for their new roles.

In all, this lightweight book is interesting, but may not be especially helpful for the scholar of organizations, communication, or rhetoric. It distills the lessons of other 4GW texts into a practical guide that works best for leaders of armed forces. Those of us who aren't in this hierarchy, however, can still learn something from the authors' brief history of warfare and their claim that 4GW arises from the crisis of the legitimacy of the state.